Curcusone C, as a diterpenoid compound, has been isolated and identified by solvent extraction and column chromatography from Jatropha curcas. This paper investigated the anti-cancer potential of Curcusone C on human ovarian cancer SK-OV-3 cells. The results in vitro demonstrated that Curcusone C significantly suppressed proliferation of SK-OV-3 cells in dose-dependent manner, with the IC50 value as 160 nmol/L under treatment with Curcusone C for 48 h. Curcusone C also markedly induced the apoptosis of SK-OV-3 cells, which showed typical apoptotic features including blebbing at the membranes and condensed chromatin with DAPI staining. In addition, Western blot clearly confirmed that the apoptotic effect was associated with activation of the cleavage of PARP, leading to the inhibitory effect of SK-OV-3 cells. All together, these findings suggest that Curcusone C may be a promising antitumor lead compound for prevention and treatment of ovarian cancer.